Our vindication comes to us from God due to the Lord's steadfast love. The Lord is faithful, we just need to realize his faithfulness and walk in it. How often do we succumb to the heresy that teaches us when we have more faith in God, we will reap more benefits? I speak mainly of the people who teach such in connection with physical healings and such. "If you only had greater faith in the Lord, he would heal you." Teachings of that manner are detrimental to our understanding and thoughts. Did not Christ say that if you had faith like a mustard seed (just an FYI, a mustard seed is really, really small) you could move mountains and command trees to be planted in the sea? Christ obliterates our requests for more faith by showing what we are to have faith in, namely, the power of God. Small faith in a big thing (God's power) glorifies God as being powerful and faithful, not ourselves. Small faith in God brings marvelous things.
Got a little sidetracked...back to Psalm 26. John Calvin comments on this passage:
"the prophet declares in what manner he pursued his course in the midst of such powerful temptations, telling us that it was by setting the goodness of God, which so carefully preserves his servants, before his eyes, lest, declining to evil practices, he might deprive himself of his protection; and by confiding in his faithfulness, he possessed his soul in patience, firmly persuaded that God would never forsake his faithful people who trusted in him. And certainly, had he not relied upon the goodness of God, he could not have so constantly prosecuted the path of integrity amidst such numerous and such severe assaults."
Confide in faithfulness. If God's goodness is not pursued, considered, and relied upon, one cannot hope to persevere through temptations and assaults.
It is one thing to say "renounce ungodliness". It is a complete saying to say "renounce ungodliness by seeing the treasure in Christ and trusting in His faithfulness towards you."